The present invention relates to an ink mist type high speed printer.
The operational speed of an information processing system including a computer system has recently been improved, thus requiring the use of a high speed peripheral device including a printer. A conventional high speed printer is a line printer with a type drum or a type train. However, this line printer has many disadvantages, some of which are that the operational speed is not sufficient for the latest information processing system, and the process involves a high level of noise and/or limitation of the number of printing types. In order to overcome these disadvantages of the prior line printer, some high speed printers with new operational principles have been developed. Among them, one of the most promising is an ink mist printer. The ink mist type printer operates at high speed, i.e. 8,000 lines per minute, with a low sound noise level. Further, it can type not only alphanumeric characters but also Chinese or Japanese characters.
The operational principle of an ink mist type printer is that an ion stream generated by corona discharge passes through apertures of an aperture board and ionizes an ink mist, and the movement of the electrically charged ink mist is accelerated by a negative electrode and is attached to paper according to the pattern of characters.
The disadvantage of the prior ink mist type printer was that dust obstructs apertures in the aperture board and prevents the passage of the ions. The obstructed apertures create incompletely printed characters and the source of the trouble cannot be located until the printing operation is actually completed, therefore wasting both paper and operational time.
Further, the dust created on the edges and/or perfurated holes of paper is apt to obstruct the abovementioned apertures.